The Brown University Population Studies and Training Center (PSTC) submits this application for an NICHD R24 Population Center grant with a request for $349,604 in direct costs for the first of five-years. The R24 Population Center program is the successor to the P30 Population Center grant that the PSTC has held since 1991. This request is based on the quality of the scientific program and its impact on the field, quality and potential impact of proposed infrastructure program, research competence of key personnel, institutional commitment and environment, and cost-efficiency of proposed infrastructure program in relation to the goals of the DBSB. The proposed level of support is based upon the PSTC's increased pace of research activity, as evidenced by published books and papers and external research funding, and the level of resources committed by Brown University to the Center. The PSTC proposes three research support cores (administration, computing services and information), a developmental infrastructure core, and a cooperative infrastructure core partnering with the Institute of Urban Research at Morgan State University. Population-related research activity at Brown benefits from the presence of strong and coherent groups of researchers within each of the key disciplines in combination with flexible institutional boundaries that permit and encourage interaction across disciplinary lines. The fact that there are critical masses of population- related researchers within each of the disciplines ensures that PSTC researchers discuss and incorporate methodological approaches at the highest appropriate level and ensures that junior researchers and graduate students with population interests are well grounded in their respective disciplines. This combinations of inter- and intra- disciplinary strength is readily evident in the five innovative "idea cores" that we use to summarize research activities at the PSTC.